/Engine/Source/Runtime/Analytics/AnalyticsET/Public/AnalyticsFlowTracker.h
End an existing flow step by GUID
bool EndSubFlow ( const [FGuid](API\Runtime\Core\Misc\FGuid) & SubFlowGuid, bool bSuccess, const [TArray](API\Runtime\Core\Containers\TArray)< [FAnalyticsEventAttribute](API\Runtime\Analytics\FAnalyticsEventAttribute) > & AdditionalAttributes )